So, beneath the surface. My initial idea was someone swimming under a frozen lake. It would be an overhead 2D shooter, similar to Galaxian, where you would fend off fish and swim for air holes. This might be a bit too depressing as you’re constantly struggling just to breathe.
After that I thought of Spelunky, which seems perfect for beneath the surface, but has been done (obviously). I think there will be plenty of games around digging or tunnelling so I’m trying to avoid that. This may change!
I was trying to go a bit deeper with the theme (pun intended) by looking at mysteries which have a truth beneath the surface, or people, who can be completely different things beneath the surface.
For now I’m going to get started on a Galaxian clone and see where I go from there.